(Vancouver, WA)  --  A man who's accused of murdering a Vancouver woman and burning down a market while she was inside is scheduled to appear in court today.  Clark County deputies say 21-year-old Mitchell Heng was arrested yesterday and a search warrant was executed at his Vancouver apartment.  Investigators say 47-year-old Amy Hooser was found dead in what was left of the Oasis Market on 134th Avenue.  The blaze originated inside the market and spread to other buildings before it was extinguished.